Stuck on him like gum on a hot summer day 🙃

There’s this guy I like. We used to date and he broke up with me because he got really busy and stuff. Fly forward, I transferred to a different school but still live in the same area. He’s a senior and I’m a sophomore. We talk to each other on and off but I’m starting to fall for him. I don’t know what to do. He knows I like him, and we’ve hung out a couple of times. During those times we’ve cuddled, made out, and had sex. He’s expressed some interest in me before, saying things that are flirty and such. I had the fear that he was using me for sex, and we talked about it and he swore he wasn’t and that we could stop if I wanted to. I told him that it was fine as long as he wasn’t using me and I also expressed my interest in him then. My fear now is that he will get back together with his other ex... I don’t want to get hurt again but I really want to be with him. He makes me happy, and he’s really understand and listens to all of my problems. I’m just scared. Does anybody have any advice or help?